Genome Hacking Could Reverse-Engineer Extinct Woolly Mammoth

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Genome Hacking Could Reverse-Engineer Extinct Woolly Mammoth

It might not make sense to pull woolly mammoths from the Ice Age into an age of global warming, but resurrecting that lost species just became a bit less far-fetched.

Using hair from 20,000-year-old specimens preserved in Siberian tundra, an international team of scientists finished a draft genome sequence of Mammuthus primigenius.

About one-fifth of the genome remains unidentified, but that should take just a few more years and scans. Once complete, it could be a template for would-be mammoth makers.

"It may one day become possible," said Pennsylvania State University biochemist and study co-author Stephan Schuster, "to mammoth-ify an African or Asian elephant genome."

Schuster's team was concerned solely with sequencing, not bringing back the mammoth. Nor were such potential resurrection efforts the most scientifically noteworthy implication of the research, published Wednesday in Nature. As the first sequence ever made with cells taken solely from hair, the genome is a tour-de-force of modern DNA sequencing technology.The researchers also found that certain genes conserved intact across the animal kingdom had mutated in mammoths, suggesting a radical and as-yet-unknown cold-weather adaptation.

But those results don't stir the imagination as do daydreams of woolly mammoths, extinct for six millennia but maintained in cultural memory, thundering across the 21st century. The obstacles to such biotechnological time travel are significant — but scientific advances are coming fast.

The first fragment of woolly mammoth genome was sequenced just two years ago, and researchers have since deciphered their mitochondrialDNA. And though some hypothetical methods of mammoth restoration —building a genome from scratch and putting it inside an elephant egg, or fertilizing an elephant egg with mammoth sperm — pose mammoth-sized technical problems, Schuster suggests a hack: working backwards from modern elephants.

"We've identified most of the differences between mammoths and African elephants. One could imagine reverse-engineering an elephant genome to become more like a mammoth," he said.

Schuster's plan won't be easy, but it may be possible. Less-complicated but fundamentally similar reverse-engineering is already used in mice and farm animals.

It's certainly easier than coding a mammoth genome from scratch: The first wholly synthetic genome, constructed last year by the J. CraigVenter institute, contained about 600,000 base pairs of DNA, compared to 4,000,000,000 in the mammoth genome. And using a 10,000-year-old cell for reproductive purposes is — in an already far-fetched discussion —especially unlikely.

"Japanese researchers have tried to do this for more than ten years by looking for intact nuclei from mammoth tissue, and they got nowhere,"said Schuster. "It's absolutely obvious why: the genome stored in those chromosomes is completely shattered."

But even though modern elephants and woolly mammoths are quite similar, having diverged less than the 98 percent-genetically-identical humans and chimpanzees, reverse-engineering won't be easy.

"It's easy to make one or two changes, and they're suggesting at least20,000," said George Seidel, a Colorado State University animal reproduction expert who was not involved in the study. "And will an elephant egg process that information in such a way as to function correctly?"

Nevertheless, even Seidel said that re-creation "is not out and out impossible," and raised the possibility of making elephant-mammoth hybrids to serve as an intermediate species on the path to a full, modern woolly mammoth.

A modern mammoth could easily be introduced in their ancestral Siberian homes, said Schuster. They would face less competition from humans than elephants in Africa, and be a star attraction of the newly-openedPleistocene Park.

But just because something can be done doesn't mean it should, he said.

"From a scientific perspective, I think we would learn very little from doing this. A lot of what you want to learn about body plan and tissues we can get just by studying the carcasses," said Schuster.